Field of the Invention
The present invention relates to a light-emitting device, and more particularly to a light-emitting diode chip including a reflective metal layer.
Description of the Related Art
Various light-emitting devices have advanced with development and advances in technology to satisfy consumers in the modern world. Among the various light-emitting devices, there has been a trend for light-emitting diodes (LEDs) to gradually replace traditional illuminated devices (for example, fluorescent lamps and incandescent lights) due to advantages such as low heat generation, low power consumption, their long lifespan, and small size.
Generally, an LED chip includes an LED and an electrode layer electrically coupled to the LED. The electrode layer may include a reflective metal layer, which reflects light emitted from the LED to the outside environment, such that the light efficiency of the LED chip can be further improved.
Aluminum or silver is a common material for the reflective metal layer since it is highly reflective of visible light. Aluminum or silver, however, are prone to deterioration due to occurrence of electro-migration under high-current operation, which adversely impacts the light efficiency and the reliability of the LED chip.
Therefore, there is a need for a novel reflective metal layer that is capable of mitigating electro-migration therein while maintaining the reflectivity thereof, thereby improving the overdrive performance of the LED chip.